Sabri Koraltan (Vienna): Nonuniform magnetic spin textures for sensing, storage and computing applications

Spintronic materials underpin many modern technologies, from harddisk drives to magnetic sensors. While these applications traditionally rely on uniform magnetization states, recent advances focus on nonuniform magnetic textures such as vortices, and skyrmions. In my doctoral thesis, I explored such textures for sensing, storage, and computing applications [1]. The first part of my talk covers the discovery and characterization of spin textures with arbitrary topological charge in ferromagnetic [Co/Ni] multilayers [2]. Using simulations and experiments, we demonstrate coexisting higher-order skyrmions and antiskyrmions and uncover their distinct dynamics under spin-transfer torques. The second part presents a three-dimensional magnetic-field sensor with a wide linear range and intrinsic offset cancellation, enabled by spin-orbit torque symmetry in a [W/CoFeB/MgO]10 multilayer that stabilizes stripe domains and skyrmions [3]. I will show, through experiments and micromagnetics, how spin-orbit torques reshape the magnetic state at high current densities to achieve full 3D sensing, with topological transitions detected electrically via the anomalous Hall effect.

[1]SK (2025), PhD Thesis, doi:10.25365/THESIS.77909 
[2] MH, SK et al., Nat. Phys. 20 (2024) 615*622 
[3] SK et al., arXiv:2403.16725 (2024)